title: Association between HLA-A alleles and Alzheimer's disease in a southern Chinese community.
abstract: OBJECTIVE
  HLA-A is a locus of the major histocompatibility complex situated on chromosome 6p21.3. Several genome-wide linkage analyses suggested that a putative locus predisposition for Alzheimer's disease (AD) is found on chromosome 6p21. In this study, we investigated the association between HLA-A alleles and AD in a Chinese community.
  
  
  METHODS
  Fine genotyping of 160 Chinese AD and 167 age-matched nondemented subjects was performed for the first time by sequence-based typing of the HLA-A locus.
  
  
  RESULTS
  We found that HLA-A2 carriers (including prevalent alleles, 0201, 0203 and 0207) were more prevalent in the AD group; the frequency of HLA-A2 was increased in AD patients versus controls, but the difference was not significant after Bonferroni correction for the number of alleles tested (p = 0.075). A gene-gene interaction was observed between ApoE and HLA-A, the presence of HLA-A24 (particularly the prevalent allele 2402) might act as another independent risk factor of developing AD for subjects not carrying the ApoE epsilon4 allele (relative risk = 2.98, 95% CI = 1.14-8.24). Carriers of HLA-A2 had an earlier onset of AD by 2.4 years (p = 0.030) and HLA-A2 interacted with ApoE epsilon4 in modulating the age at onset in AD.
  
  
  CONCLUSIONS
  This study suggested that HLA-A may be involved in the pathogenesis of AD.
authors.affiliation: Department of Chemical Pathology, Faculty of Medicine, Chinese University of Hong Kong, Shatin, Hong Kong, SAR, China.
authors.forename: Suk Ling
authors.initials: SL
authors.lastname: Ma
authors.forename: Nelson Leung Sang
authors.initials: NL
authors.lastname: Tang
authors.forename: Cindy Woon Chi
authors.initials: CW
authors.lastname: Tam
authors.forename: Victor Wing Cheong
authors.initials: VW
authors.lastname: Lui
authors.forename: Eddie Wai Chui
authors.initials: EW
authors.lastname: Suen
authors.forename: Helen Fung Kum
authors.initials: HF
authors.lastname: Chiu
authors.forename: Linda Chiu Wa
authors.initials: LC
authors.lastname: Lam
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000235:genetics*; D001057:Apolipoproteins E / Q000235:genetics; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004311:Double-Blind Method; D005091:Exons / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D015234:HLA-A Antigens / Q000235:genetics*; D006579:Heterozygote; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis
chemical_list: D001057:Apolipoproteins E; D015234:HLA-A Antigens; D004247:DNA